The Cortex -M0+ architecture is designed to provide chip-makers with the means to build microcontrollers that require "ultra low power" but are capable of 32-bit processing. Arm says it went back to the drawing board to create the new processor cores which measure 1mm by 1mm in size. It says the microcontrollers should draw around a third less energy than their predecessors, which only offered 8 and 16-bit capabilities.

How is this any way related to Raspberry Pi?
The Pi is positioned as low-cost computer, with GPU and peripherals etc.
and this M0 seems to be positioned as "high end micro-controller".
A new Arduino however sounds like a better fit, now that they've announced an ARM version anyway.

Also, the news doesn't speak anything about availability, I'm guessing it'll be a while until devices using it are available.